The phenotypic frequencies of HLA-A*02:07, A*26:01, A*30:04, or A*33:03 alleles were compared between a subset of patients having a particular clinical manifestation (genital ulcers, skin lesions, positive pathergy test, uveitis, arthritis, or vascular lesions) and controls (Table 4). Here, HLA-A is linked to Genital ulcers.